Gary Pruitt, the President and CEO of the Associated Press, discusses the leak investigation that led to his reporters' phone records being subpoenaed by the Justice Department on CBS's "Face the Nation" in Washington Sunday.

"Officials that would normally talk to us and people we talk to in the normal course of news gathering are already saying to us that they're a little reluctant to talk to us," Pruitt said on CBS's "Face The Nation" program. "They fear that they will be monitored by the government."

The Justice Department told the AP on May 10 that it had earlier seized records of more than 20 of its phone lines for April and May 2012. The seizure was part of an investigation of media leaks about a foiled terrorism plot.

"Approximately a hundred journalists use these telephone lines as part of news gathering," Pruitt said. "And over the course of the two months of the records that they swept up, thousands upon thousands of news-gathering calls were made."

The White House has said that President Barack Obama learned about the Justice Department's record seizure from press reports and had no prior knowledge of the action. Obama's administration is fielding concerns on several incidents that raise questions about its transparency.

Pruitt said the Justice Department claimed an exception to its own rules that required them to notify the AP of such a record seizure by saying that such a disclosure would have posed a substantial threat to the investigation.

"But they have not explained why it would and we can't understand why it would," Pruitt said. "We never even had possession of these records, they were in the possession of our telephone service company and they couldn't be tampered with."

Government officials have told Reuters that the AP phone records were just one element in an ongoing sweeping U.S. government investigation into media leaks about a Yemen-based plot to bomb a U.S. airliner, prompted by a May 7, 2012 AP story about the operation to foil the plot.

"We don't question their right to conduct these sort of investigations," Pruitt said. "We think they went about it the wrong way, so sweeping, so secretively, so abusively and harassingly."

Pruitt said the AP would have sought to narrow the scope of the record seizure through courts had it been notified, instead of "the Justice Department acting on its own, being the judge, jury and executioner, in secret."

Reuters was one of nearly 50 news organizations that signed a letter to Attorney General Eric Holder complaining about the AP phone record seizures.